The space requirement comes from two things: the diagrams on the panels are actually fairly complex with lots of controls thwt fit mostly inside the diagrams themselves. Operators in the room should be able to scan the whole diagram easily from a central position.

Thw size of the room then becomes a requirement because all the panels need to be oriented inwards, not occluded and they can't shrink down too much because the controls need to fit.

Backside of the panels. This might help you understand why the amount of space used is not at all extravagant. We're spoiled with our disposable, tiny electronics. Those things were meant to last decades.